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Question
While doing an experiment with potentiometer (Figure) it was found that the deflection is one sided and (i) the deflection decreased while moving from one end A of the wire to the end B; (ii) the deflection increased. while the jockey was moved towards the end B.
- Which terminal + or – ve of the cell E1, is connected at X in case (i) and how is E1 related to E?
- Which terminal of the cell E1 is connected at X in case (ii)?
Solution
- If the current in auxiliary circuit (lower circuit containing primary cell) decreases, and potential difference across A and jockey/increases. Then deflection in galvanometer is one-sided and the deflection decreases while moving from one end ‘A ’ of the wire to the end ‘S’. And clearly, this is possible only when positive terminal of the cell E1 is connected at X and E1 > E.
- If the current in auxiliary circuit increases, and potential difference across A and jockey J increases. Then also deflection in galvanometer is one-sided. And this is possible only when negative terminal of the cell E1 is connected at X.
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